The objectives of the Biochemistry and Genomics Laboratory of the Human Metabolic and Genetic Core are as follows: 1. To generate plasma and cell bank on 3000 morbidly obese subjects (body mass index >40kg/m2). 2. To provide reliable automated standardized biochemical analysis on human plasma, serum, or urine to a variety of investigators carrying out human metabolic studies that relate to the regulation of caloric intake, different dietary constituents, as well as energy expenditure and human obesity. 3. To provide high throughput genotyping analysis of DNA isolated from a variety of individuals in order to relate specific mutations within genes to variability in nutritional response and body composition, caloric intake, and human obesity. 4. To train investigators in these measurements.